Any term that conflates nuclear weapons with any other kind of weapon is bound to be a poor descriptor. But the U.S. government has reached peak absurdity by labeling a rocket-propelled grenade a weapon of mass destruction.

Technically, Eric Harroun, a U.S. Army veteran who joined the rebellion in Syria, has only been charged with using a “destructive device.” (More on him in a second.) But U.S. law isn’t particularly diligent about differentiating dangerous weapons from apocalyptic ones. The affidavit of FBI agent Paul Higginbotham undergirding Harroun’s recent arrest and charge sums it up like this: “There is probable cause to believe that, in or about January 2013 to March 2013, Eric Harroun conspired to use a weapon of mass destruction, i.e. a Rocket Propelled Grenade, outside of the United States, in violation of 18 U.S.C. 2332a(b).”

Harroun will have his day in court to contest the facts surrounding his case. But federal law has established the absurdity that a rocket-propelled grenade is a weapon of mass destruction. If you follow the rabbit hole of the statute referenced in Higginbotham’s affidavit, any citizen who uses “a weapon of mass destruction outside of the United States shall be imprisoned for any term of years or for life.” The statutory definition of “weapon of mass destruction” refers to “any destructive device as defined in section 921 of this title,” which in turn includes: a “rocket having a propellant charge of more than four ounces.”

Other weapons of mass destruction, legally speaking: Bombs. Grenades. Mines. Missiles “having an explosive or incendiary charge of more than one-quarter ounce.”

More: Let’s All Stop Saying ‘Weapons of Mass Destruction’ Forever